On 04/29/11 11:58, michael.hennerich@xxxxxxxxxx wrote:
> From: Michael Hennerich <michael.hennerich@xxxxxxxxxx>
>
> Don't issue the same message twice, use two transfers and group them together
>
> Signed-off-by: Michael Hennerich <michael.hennerich@xxxxxxxxxx>
Acked-by: Jonathan Cameron <jic23@xxxxxxxxx>
> ---
> drivers/staging/iio/gyro/adxrs450_core.c | 58 ++++++++++++++---------------
> 1 files changed, 28 insertions(+), 30 deletions(-)
>
> diff --git a/drivers/staging/iio/gyro/adxrs450_core.c b/drivers/staging/iio/gyro/adxrs450_core.c
> index dcd88ff..a1a71b7 100644
> --- a/drivers/staging/iio/gyro/adxrs450_core.c
> +++ b/drivers/staging/iio/gyro/adxrs450_core.c
> @@ -40,29 +40,28 @@ static int adxrs450_spi_read_reg_16(struct device *dev,
> struct iio_dev *indio_dev = dev_get_drvdata(dev);
> struct adxrs450_state *st = iio_dev_get_devdata(indio_dev);
> int ret;
> - struct spi_transfer xfers = {
> - .tx_buf = st->tx,
> - .rx_buf = st->rx,
> - .bits_per_word = 8,
> - .len = 4,
> + struct spi_transfer xfers[] = {
> + {
> + .tx_buf = st->tx,
> + .bits_per_word = 8,
> + .len = 4,
> + .cs_change = 1,
> + }, {
> + .rx_buf = st->rx,
> + .bits_per_word = 8,
> + .len = 4,
> + },
> };
> - /* Needs to send the command twice to get the wanted value */
> +
> mutex_lock(&st->buf_lock);
> - st->tx[0] = ADXRS450_READ_DATA | reg_address >> 7;
> + st->tx[0] = ADXRS450_READ_DATA | (reg_address >> 7);
> st->tx[1] = reg_address << 1;
> st->tx[2] = 0;
> st->tx[3] = 0;
> - spi_message_init(&msg);
> - spi_message_add_tail(&xfers, &msg);
> - ret = spi_sync(st->us, &msg);
> - if (ret) {
> - dev_err(&st->us->dev, "problem while reading 16 bit register 0x%02x\n",
> - reg_address);
> - goto error_ret;
> - }
>
> spi_message_init(&msg);
> - spi_message_add_tail(&xfers, &msg);
> + spi_message_add_tail(&xfers[0], &msg);
> + spi_message_add_tail(&xfers[1], &msg);
> ret = spi_sync(st->us, &msg);
> if (ret) {
> dev_err(&st->us->dev, "problem while reading 16 bit register 0x%02x\n",
> @@ -125,11 +124,17 @@ static int adxrs450_spi_sensor_data(struct device *dev, u16 *val)
> struct iio_dev *indio_dev = dev_get_drvdata(dev);
> struct adxrs450_state *st = iio_dev_get_devdata(indio_dev);
> int ret;
> - struct spi_transfer xfers = {
> - .tx_buf = st->tx,
> - .rx_buf = st->rx,
> - .bits_per_word = 8,
> - .len = 4,
> + struct spi_transfer xfers[] = {
> + {
> + .tx_buf = st->tx,
> + .bits_per_word = 8,
> + .len = 4,
> + .cs_change = 1,
> + }, {
> + .rx_buf = st->rx,
> + .bits_per_word = 8,
> + .len = 4,
> + },
> };
>
> mutex_lock(&st->buf_lock);
> @@ -139,15 +144,8 @@ static int adxrs450_spi_sensor_data(struct device *dev, u16 *val)
> st->tx[3] = 0;
>
> spi_message_init(&msg);
> - spi_message_add_tail(&xfers, &msg);
> - ret = spi_sync(st->us, &msg);
> - if (ret) {
> - dev_err(&st->us->dev, "Problem while reading sensor data\n");
> - goto error_ret;
> - }
> -
> - spi_message_init(&msg);
> - spi_message_add_tail(&xfers, &msg);
> + spi_message_add_tail(&xfers[0], &msg);
> + spi_message_add_tail(&xfers[1], &msg);
> ret = spi_sync(st->us, &msg);
> if (ret) {
> dev_err(&st->us->dev, "Problem while reading sensor data\n");
> --
> 1.6.0.2
>
>
>
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